基于热力非耦合数值模拟的轮胎模具结构优化

以1188型号轮胎模具为例,运用ANSYS软件对模具进行热分析与结构应力分析,得出模具热分析与结构应力分析的结果。以改善模具型腔内温度的均匀性和花纹块上的温度分布为模具结构的优化目标,提出了改变花纹块与弓形座之间接触方式的模具结构调整方案,并对改进后的模具结构进行应力分析与热分析。结果表明:改变花纹块与弓形座的接触方式后,花纹块上、下两端的温差由1.933℃减小为0.01℃,模具型腔温差由2.319℃减小至0.989℃,模具型腔温度均匀性好;同时,花纹块上、下两端拐角处的应力值明显减小,应力集中也有明显改善,有利于提高硫化轮胎的使用性能和延长其使用寿命。     

轮胎模具合体结构的设计与数值模拟

介绍了一种合体结构轮胎模具,主要说明其特点及应用场合,论述合体结构模具设计过程及应注意的问题。应用ANSYS软件对合体结构模具和原结构模具进行应力分析与热分析,依据分析结果与数据,从模具型腔应力分布、模具型腔温度分布的均匀性以及花纹块温度分布情况,模具质量与体积等方面对合体结构模具与原结构模具进行对比。结果表明,合体结构模具有利于提高轮胎产品的性能。     

热分析与热力耦合分析的轮胎模具温度场分布

以63.5#硫化机使用的1188型号的轮胎模具为例,模具的型腔由硫化12R22.5规格轮胎的花纹块与上、下侧板组合而成,以此模具结构为模型,利用ANSYS有限元分析软件,对模具结构进行了热分析、热力耦合分析与结构应力分析,热分析过程中只考虑硫化机的加热源对模具温度场分布的影响,热力耦合分析考虑了热源与受力同时作用下,模具型腔温度和应力的分布情况。以热分析与热力耦合分析的结果为依据,从模具平均温度、花纹块温度、花纹块上、下端温差等方面对2种方法的效果进行了对比,给出结构应力分析的模具型腔应力分布曲线与热力耦合分析的模具型腔应力分布曲线。     

斜平面导向轮胎模具底座耐磨板结构性能分析

斜平面模具底座耐磨板在闭模时起到支撑弓形座的作用,底座耐磨板磨损过大会导致侧板与花纹圈结合处出现错台,影响硫化轮胎的表面质量,底座耐磨板的形状大小也会影响模具传热过程中型腔内部的温度均匀性。通过对底座耐磨板的磨损和传热模拟分析可知:当底座耐磨板结构为梯形时,模具工作1.5万次时闭模瞬间磨损量可达0.083 mm,且花纹块上下点温差较大;当底座耐磨板结构为矩形时,模具工作1.5万次时闭模瞬间磨损量为0.32 mm,模具磨损量较大,但硫化时花纹块的温差较小。     

活络模具结构影响轮胎温度场的模拟分析

建立9.00R20轮胎模具的三维模型,为分析活络模具结构对轮胎温度场的影响,通过应用ANSYS Workbench有限元软件对轮胎活络模具温模过程进行了数值模拟分析,获得轮胎胎面的温度场分布,并据此提出改进模具的结构,解决轮胎胎面存在温差的现象.结果表明:与原模型相比,不同模具结构对轮胎温度场的影响不同,通过改进模具结构,使轮胎胎面的温差减小,同时缩短轮胎的硫化时间,节约能耗,降低成本.     

弓形座结构对轮胎模具温度场的影响

弓形座既是中套传递给花纹块硫化温度的载体,也是与花纹块精确配合实现花纹块径向运动的重要部件。根据轮胎结构及橡胶传热特性,有效地进行模具结构设计,使模具硫化温度建立在合理的硫化温度分布区块。通过对不同弓形座结构的计算机热传导模拟、分析花纹块胎肩处的硫化温度可知:增加弓形座腰带处尺寸,可使胎肩处硫化温度差减小至0.3~0.4,有利于该处橡胶硫化的同质性。     

轮胎模具电火花加工型腔深度在线测量技术研究

对轮胎模具电火花加工的型腔深度误差进行分析研究,提出了一种在线测量方法,利用数控系统对测量数据进行统计分析,并进行在线修整,提高了轮胎模具的型腔深度精度。     

轮胎活络模具中套耐磨板的磨损研究

介绍了斜平面导向活络模的结构及开合过程。明确了中套耐磨板磨损量与花纹块立面间隙之间的关系。通过Deform-3D模拟,估算出了1188型号壳体中套耐磨板在特定条件下的Archard模型的磨损系数,建立起轮胎模具中套耐磨板与弓形座之间的磨损模型,根据该磨损模型,对某些胶边的产生就可以预判和进行适时控制,从而达到提高模具生产管理水平,提高轮胎质量的目的。     

底座滑板结构对花纹块温度分布的影响

轮胎模具型腔温度分布的均匀性对硫化轮胎质量非常重要,模具结构设计上的差异会使花纹块的温度分布出现较大的温差,这种温差将导致硫化轮胎的胎面质量不均匀,从而影响轮胎性能。利用ADINA有限元软件,针对全钢轮胎模具底座滑板结构,对花纹块温度分布进行了模拟分析,结果表明:底座滑板结构的变化,对12.00R20规格的轮胎模具结构影响较大。     

圆锥面与斜平面轮胎模具传热模拟分析

介绍了圆锥面与斜平面轮胎模具的结构特点,以Y1188壳体9.00R20、12.00R20的2种规格模具为例,利用Abaqus软件对2种规格的圆锥面与斜平面轮胎模具进行传热模拟分析。结果表明:9.00R20规格的轮胎模具型腔温度分布要优于12.00R20规格的轮胎模具,斜平面轮胎模具型腔温度分布要优于圆锥面轮胎模具,与斜平面轮胎模具相比,圆锥面轮胎模具升温快,9.00R20和12.00R20规格的圆锥面轮胎模具分别比对应的斜平面轮胎模具达到轮胎硫化要求温度的预热时间减少26 min和20 min,模拟结果为合理的选择轮胎模具进行轮胎硫化提供理论指导。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Quantitative Analysis of the Crystallographic Orientation Relationship Between the Martensite and Austenite in Quenching–Partitioning–Tempering Steels

The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.     

The Mirror with Patterns of Auspicious Animals and Grapes——Exquisite cast mirror and the technology of surface tin-enrichment by rubbing-in and infiltration of tin-rich powder

<正>Bronze mirrors were used by the Chinese people before the introduction of the glass mirror.Only after it was replaced by the glass mirror did the bronze mirror gradually retreat from people's lives.Different styles of bronze mirrors were made in different historical periods,particularly in the Warring States Period,the Han and Tang Dynasties,which were the three peaks of the development of bronze mirror arts in ancient China.The casting techniques were exquisite.The surface of the bronze mirror was smooth and bright enough to reflect one's image,and there were scarcely any casting defects on the mirror surface.On the back of the bronze mirror,there were rich depictions of Arts and Humanities,and the ornamentations were also     

The 9th China International Diecasting Congress & Exhibition

The 9th China International Diecasting Congress ＆ Exhibition was held on July 22-24, 2014 at Shanghai New International Expc Centre. This exhibition was the most successful over the years, with over 6890 visitors and 155 exhibitors, and the exhibition area increased by 30% from 9,500 square meters in 2012 to 12340 square meters. Die casting enterprises from a total of 24 countries and regions, including China mainland, Chinese Taiwan and Hong Kong, South Korea, Japan, Germany, India, Thailand, Malaysia, the United States, Russia, Australia, Iran, Ukraine, Brazil, Colombia, Singapore, Austria, Canada, Croatia, France, Turkey, United Kingdom, Vietnam, attended the congress and exhibition.     

Introduction of the Fluid Control Engineering Institute of Kunming University of Science and Technology

正The Fluid Control Engineering Institute of Kunming University of Science and Technology was set up in 1996.The researches of institute concentrate on electro-hydraulic(pneumatic)servo/proportional control and hydromechatronics.The Institute is committed to research and development of electro-hydraulic control of high-end technical equipment in ferrous metallurgy refining produc-     

RARE METALS Volume Contents

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Antimony Induced Crystallization of Amorphous Silicon

Antimony induced crystallization of PVD (physics vapor deposition) amorphous silicon can be observed on sapphire substrates. Very large crystalline regions up to several tens of micrometers can be formed. The Si diffraction patterns of the area of crystallization can be observed with TEM (transmission electron microscopy). Only a few and much smaller crystals of the order of 1μm were formed when the antimony layer was deposited by MBE (molecular beam epitaxy) compared with a layer formed by thermal evaporation. The use of high vacuum is essential in order to observe any Sb induced crystallization at all. In addition it is necessary to take measures to limit the evaporation of the antimony.     

A CUMULATIVE FATIGUE DAMAGE RULE UNDER THE ALTERNATIVE OF CORROSION OR CYCLIC LOADING

Fatigue damage increases with the applied loading cycles in a cumulative manner and the material deteriorates with the corrosion time. A cumulative fatigue damage rule under the alternative of corrosion or cyclic loading was proposed. The specimens of aluminum alloy LY12-CZ soaked in corrosive liquid for different times were tested under the constant amplitude cyclic loading to obtain S-N curves. The test was carried out to verify the proposed cumulative fatigue damage rule under the different combinations among corrosion time, loading level, and the cycle numbers. It was shown that the predicted residual fatigue lives showed a good agreement with the experimental results and the proposed rule was simple and can be easily adopted.